Device for controlling the tension of a longitudinally moving wire



e. H. LELAND 2,6,40,663 DEVICE FOR CONTROLLING THE TENSION OF A LONGITUDINALLY MOVING WIRE June 2, 1953 3 Sheets-Sheet 1 Filed Feb. 1, 1949 INVENTOR. A4 Aid/7N0 Juan Ey- G. H. LELAND DEVICE FOR CONTROLLING THE TENSION OF A LONGITUDINALLY MOVING WIRE June 2, 1953 3 Sheets-Sheet 2 Filed Feb. 1, 1949 INVENTOR. 950,865 M fl/7N0 I June 2, 1953 G. H. LELAND 2,640,663

' DEVICE FOR CONTROLLING THE TENSION OF A LONGITUDINALLY MOVING WIRE F iled Feb. 1, 1949 s Sheets-Sheet 3 INVENTOR. 650 965 H. LEA/7N0 Patented June 2, 1953 DEVICE FOR CONTROLLING THE TENSION OF A LONGITUDINALLY MOVING WIRE George H. Leland, Dayton, Ohio, assignor to G. H. Leland, 1110., Dayton, Ohio, a corporation of Ohio Application February 1, 1949, Serial No. 7:3,962

15 Claims. 1-

Thisinvention relates to a device for controlling the tension of a longitudinally moving wi-re, suchas a wire moving from a spool of wire to a coil winding device or the like.

One object or the invention is toprovide a device which automatically maintains the wire at. a uniform. tension regardless of variations in the demand forwire bythe coil winding device or other device? to which the wire is supplied.

A;further-obiect of'theinvention is to provide a. device which any variation of the tension from the desired tension will cause an adjustment of: thedevice to restore the desired tension.

A further object of the invention is to provide an. automatic constant tension adjusting device, in which: the corrective mechanism is highly sensitive, due tow the low friction and low inertia thereof.

A further object of the invention is to provide an automatic corrective, constant tension device in which the wire being: supplied is subjected to a minimum reductionin size as compared to the tension under which it is placed.

Afu-rther object of the invention is to provide a device in which the adjustment to correct the tension of the wire will be substantially instantaneous and complete, as distinguished from a step by step adjustment.

A further object of the invention is to provide a, device which can be initially adjusted to maintain the wire at a selected predetermined tension: and in which the adjustment is responsive to the pull of the wire to instantly correct any variationof the tension fromthe predetermined tension.

A further object of the invention is to provide a device in which the rotation of the wire supporting: pull'eyby the wire is. controlled by a friction element which is responsive to variations inthe-pull: oi the wire to increase or decrease the resistance to the rotation of the pulley.

A further object of the invention is to provide such a tension controlling device with means whereby the wire may be freely and uniformly withdrawn froma stationary spool of wire.

Other objects of the invention may appear as the device is described in detail.

In the accompanying drawings Fig. 1 is a side elevation of a tension-mg device embodying the invention; Fig. 2 is a longitudinal sectional view of such a device, showing the mounting therefor in elevation; Fig. 3 is a front elevation of the tensioning device; Fig. 4 is a section taken on the line 4-4 of Fig. 2; Fig. 5 is a detail section takenon the line. 6-5 of. Fig. 4; 6 is a. sec- 2. tional view of a wire guide; and Fig. 7 isa plan view of a portion of the wire guide.

In these drawings I have illustrated one em-. bodiment of the invention and have shown the same as designed primarily for controlling the tension of a wire as the. latter is advanced by a coil winding device or the like. It is to bev understood, however, that the device as a whole as well as the several parts thereof may take various forms, may be assembled in variousways, and may be used in connection with. wire. working devices of various kinds, without departing from the spirit of the invention.

In that embodiment of the invention here illustrated the device comprises a pulley In; about which the wire passes as it moves from the spool, or other source of supply, to the coil winding device, and which is rotated by the moving wire, and the rotation of the pulley is controlled by a friction element, or brake, H, which is adjustable to regulate the frictional resistance to the rotation of the pulley, means being provided to automatically control the adjustment of the triotion element in accordance with variations in the tension of the wire from a predetermined tension. The pulley and the tension element are mounted on a shaft [2 which is secured to and supported by a rigid member l3. The supporting member I3 may be mounted on any suitable structure and is here shown as mounted on the reduced portion I4 of a stud which is rigidly secured to a bracket I6 mounted on a standard ll, as by a clamp [8. The supporting member it may be of. any suitable character but preferably it comprises a relatively narrow rigid plate, or arm, it which is provided at one end with an opening through whichthe reduced portion it of the stud extends, and a nut on the reduced portion it of the stud clamps the supporting member tightly against the shoulder formed on the stud by the reduced portion there of. Thus the device as a whole is rigidly supported, with the shaft preferably in a substantially horizontal position.

The pulley is rotatably mounted on the shaft and may take various forms. As here shown it comprises a relatively thin circular body portion 2! having a central opening 22 through which a reduced portion 23 of the shaft i2 extends. The central portion of the body, about the opening 22, is oiiset inwardly from the plane of the body to provide the pulley with an outwardly facing cavity 24. Mounted in this cavity is an antiiriction bearing, the inner race 25 of. which is mounted on the reduced portion 23 of the shaft and the outer race 26 of which is secured to the wall of the cavity. The outer end portion 21 of the shaft, which extends beyond the bearing, is further reduced and screw threaded to receive a nut 28 which engages the bearing to limit the outward movement of the pulley and is operable to adjust the pulley longitudinally of the shaft. To permit the nut to move inwardly with relation to the shaft it is provided in its inner surface with the recess 29 of a diameter slightly greater than the diameter of the reduced portion 23 of the shaft. The nut 28 may be retained in its adjusted position on the shaft in any suitable manner, as by a set screw 30. The pulley is provided with a frustro-conical peripheral surface which, in the present instance, is formed by an annular, inwardly flared flange 3 I, the small diameter end of which is secured to, and preferably formed integral with, the body 2| of the pulley, the body extending radially beyond the edge of the flange, at 32, and cooperating therewith to provide the pulley with a peripheral wire receiving channel. The reduced portion M of the stud 15 extends across the major portion of the length of the device and is provided adjacent to and in the rear of the pulley with an opening in which is mounted a wire guide 33a having an opening therethrough, the end portions of which are flared in opposite directions to provide a narrow area of contact with the wire. As the wire 33 is withdrawn from the spool, 34, it passes upwardly in the rear of the pulley, through the guide 33a and about the pulley to the coil winding device, the wire being wrapped about the conical surface of the pulley in a sufficient number of turns to cause the pulley to rotate with the wire as the latter moves to the coil winding device. The spool is preferably formed of light weight material, such as aluminum, and is of such a character that it may be cast or formed from sheet metal.

The friction element 1 I may be of any suitable character and it is here shown as comprising a solid block of material, preferably metal, having an axial bore 35 to receive the shaft l2, on which it is mounted for both axial and rotary movement, and having at that end adjacent the pulley a flat surface to frictionally engage the pulley. The pulley may be provided with a friction surface, of any suitable character, to be engaged by the friction element, such as a layer of felt 3B which is secured to the inner surface of the pulley between the bearing cavity and the flange 3!. It is also desirable that the friction element be provided with means for dissipating the heat generated by the frictional contact of the pulley therewith and this means may conveniently comprise heat dissipating fins 31. Means are provided whereby the friction element may be so adjusted with relation to the pulley that when the friction element is held against rotation the pulley will rotate in engagement therewith but its rotation will be so resisted by the friction element that the wire between the pulley and the coil winding device will be maintained at a predetermined tension. The adjusting means includes means controlled by the rotation of the friction element to move the same with relation to the pulley in a direction to increase the frictional engagement between the friction element and the pulley if the tension of the wire becomes less than said predetermined tension, and to move the friction element in a direction to decrease the friction between the same a h 4 pulley if the tension of the wire becomes greater than the predetermined tension.

The adjusting means as a whole includes means controlled by the rotation of the friction element to impart axial movement thereto and this means is preferably interposed between the friction element and a stationary part of the supporting structure. Preferably an element is movably supported between the friction element and the stationary part of the structure in such a manner that it will move the friction element toward the pulley when the friction element rotates in one direction and will permit the movement of the friction element from the pulley when the friction element rotates in the other direction. In the form here shown an annular member, or plate, 38 is mounted about the shaft 12 adjacent the supporting member l3 and is held against rotation. A second annular member, or plate, 39 is connected with the friction element for movement therewith and is supported in opposed relation to the plate 38. Each of the plates 38 and 39 is provided with a series of inclined surfaces, the corresponding surfaces on the two members being arranged in opposed relation, and an antifriction element is movably supported between and in engagement with each pair of inclined surfaces. The inclined surfaces of each pair are sloped in opposite directions so that the movement of the inclined surfaces of the rotatable member 39 with relation to said inclined surfaces of the stationary member 38 in one direction will separate those surfaces one from the other and thus impart axial movement to the friction element toward the pulley, and the relative movement of said inclined surface in the other direction will release the friction element for movement from the pulley. In the preferred construction the plate 38 is provided with an annular series of relatively short arcuate grooves 40, in the present instance three, and the bottom walls of these grooves all slope in the same direction and to the same extent. The plate 39 is provided with a similar series of grooves 4| the bottom walls of which slope in a direction opposite the direction of the slope of the grooves 40. The corresponding grooves of the two series are arranged in opposed, or overlapping, relation and a ball 42, of steel or other hard material, is supported in each pair of grooves. The direction of the slope of the bottom walls of the grooves is such that when the friction element rotates in the direction of rotation of the pulley by the wire the deeper portions of the grooves 4| will be moved toward the deeper portions of the grooves 40, in engagement with the respective balls, and the axial pressure on the friction element will be relieved. When the friction element rotates in the direction opposite the direction of rotation of the pulley by the wire the shallow portions of the grooves 4! move toward the shallow portions of the grooves 40, in engagement with the respective balls, thus separating the two plates and pressing the friction element more tightly against the pulley.

An adjustable device is connected with the friction element to hold the same against rotation when the tension on the wire is of a predetermined value and to rotate the friction element in a direction to increase the pressure thereof on the pulley when the tension on the wire is less than the predetermined value, and said device is yieldable to permit the friction element to rotate in a direction to decrease its pressure on the pulley when the tension of the wire is rotary movement and axial movement with relation thereto and having continuous frictional engagement with said pulley, and adapted to be rotated by said pulley, a device connected with said brake element and tending to rotate the same in one direction, said device being yieldable to permit said brake element to be rotated in the other direction by said pulley, and means controlled by the rotary movements of said brake element for regulating the frictional engagement thereof with said pulley, said means including a movable element interposed between said brake element and said supporting member and controlled by the rotary movement of said brake ele-- ment to control the axial position of the latter, said yieldable device being adjustable to so control the force exerted thereby on said brake element that the latter will be held normally against rotation and said movable element will be retained in an intermediate position between the limits of its movement, and means for adjusting said pulley with relation to said brake element to establish said intermediate position of said movable element.

12. A device for controlling the tension of a longitudinally moving wire, comprising a supporting structure, a shaft mounted on said structure, a pulley of light weight and low inertia mounted on said shaft and about which the wire passes and which is rotated by said wire, an anti-friction bearing interposed between said pulley and said shaft, said pulley having on one side thereof a friction member of yieldable material, an element mounted on said shaft for both rotary movement and axial movement and having frictional engagement with the friction member on said pulley, and means controlled by the rotational force exerted on said element by said rotating pulley to move said element toward or from said pulley in accordance with the variations in the tension of said wire.

13. A device for controlling the tension of a longitudinally moving wire, comprising a supporting structure, a shaft mounted on said structure, a pulley of light weight and low inertia mounted on said shaft and about which the wire passes and which is rotated by said wire, an antifriction bearing interposed between said pulley and said shaft, said pulley having on one side thereof a friction member of yieldable material, an element mounted on said shaft for both rotary movement and axial movement and having frictional engagement with the friction member on said pulley, means controlled by said frictional engagement for preventing the rotation of said element by said pulley when the tension of said wire is of a predetermined value and for moving said element toward or from said pulley when said tension decreases or increases, and means for axially adjusting said pulley with relation to said element.

14. A device for controlling the tension of a longitudinally moving wire, comprising a pulley about which the wire passes and which is rotated by the wire, a normally stationary element frictionally engaging said pulley and capable of rotation thereby, means controlled solely by the rotational force exerted by said pulley on said element to move said element toward or from said pulley in accordance with variations in the tension of said wire, and means for axially adjusting said pulley with relation to said element.

15. A device for controlling the tension of a longitudinally moving wire, comprising a pulley about which the wire passes and which is rotated by the wire, a normally stationary element frictionally engaging said pulley and capable of rotation thereby, means controlled by the rotational force exerted by said pulley on said element to move said element toward or from said pulley in accordance with variations in the tension of said wire, and a member mounted on a fixed support and having a part yieldably engaging said wire beyond and adjacent to said pulley to minimize the vibration thereof.

GEORGE H. LELAND.

References Cited in the file of this patent UNITED STATES PATENTS Germany Oct. 2, 1915 

